(a) Field of the Invention
The present invention relates to a power delivery system of a hybrid electric vehicle. More particularly, the present invention relates to a power delivery system of a hybrid electric vehicle having two speed ranges in addition to speed ranges of a transmission.
(b) Description of the Related Art
Generally, a hybrid electric vehicle uses two power sources of an engine and a motor, different from an internal combustion engine vehicle.
In the prior art, a continuously variable transmission (CVT) may be used as a transmission of a hybrid electric vehicle.
In addition, power delivered by a chain from the CVT is delivered to a differential case by gears coupled to two shafts.
A speed reduction ratio of gears coupled to two shafts is determined by sizes of gears, and a problem of noise vibration harshness (NVH) may occur.
A speed reduction ratio of gears coupled to two shafts is determined by the outer diameters of the gears.
However, when a speed reduction ratio of gears coupled to two shafts is set as one, there is a problem in that neither a speed increase nor a speed reduction can be realized.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.